﻿/************************************************************************

   Extended Silverlight Toolkit

   Copyright (C) 2010-2012 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://extendedsilverlight.codeplex.com/license

   Please purchase a commercial version of this toolkit if you are using
   it in a commercial product. The commercial versions support the project,
   and also include more features for each control, priority support,
   source code, updates, removed watermark, and a proprietary license.

   Visit http://xceed.com and follow @datagrid on Twitter.

  **********************************************************************/

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq;
using System.Text;

namespace Xceed.Silverlight.Data
{
  [DebuggerDisplay( "OrderBy = {DebuggingSortOrder}" )]
  public sealed class SortRequest
  {
    internal SortRequest( IEnumerable<SortDescription> sortOrder )
    {
      if( sortOrder == null )
        throw new ArgumentNullException( "sortOrder" );

      if( !sortOrder.Any() )
        throw new ArgumentException( "At least one SortDescription must be specified.", "sortOrder" );

      m_sortDescriptions.AddRange( sortOrder.Distinct() );
      m_readOnlySortDescriptions = new ReadOnlyCollection<SortDescription>( m_sortDescriptions );
    }


    #region SortDescriptions Property

    public IList<SortDescription> SortDescriptions
    {
      get
      {
        return m_readOnlySortDescriptions;
      }
    }

    private ReadOnlyCollection<SortDescription> m_readOnlySortDescriptions; //null
    private List<SortDescription> m_sortDescriptions = new List<SortDescription>();

    #endregion

    #region DebuggingSortOrder Property

    // This property only purpose is to generate a string for the DebuggerDisplay attribute.
    private string DebuggingSortOrder
    {
      get
      {
        StringBuilder sb = new StringBuilder();
        bool isFirstDescription = true;

        foreach( SortDescription description in m_sortDescriptions )
        {
          if( !isFirstDescription )
          {
            sb.Append( ", " );
          }
          else
          {
            isFirstDescription = false;
          }

          sb.Append( "{" );
          sb.Append( description.PropertyName );
          sb.Append( "}" );

          if( description.Direction == ListSortDirection.Ascending )
          {
            sb.Append( " asc" );
          }
          else
          {
            sb.Append( " desc" );
          }
        }

        return sb.ToString();
      }
    }

    #endregion
  }
}
